I'd say that overall, traditional sources of energy are best suited for supplying large amounts of energy, say for an entire city. "Green" energy would be best for mobile equipment or remote locations.
Your both right and wrong at the same time there, aswell with your musings about efficiency.
While solar and wind power isn't as efficient as more tradional fossil fueled power, the reason that they're called renewable is why they're so good, and, the future. Fossil fuels are practically finite, the sun and wind are practically infinite. Solar panels might not be as energy efficient (and hell, hardly space efficient), however you can just crank out more of them and your only going to be wasting sunlike, which is just being wasted anyway. However, we're going to run out of coal and oil within a century or so (if someone pulls out that "300 year" crap from the 80's i'll slap you).
This is why, your right, currently it's much easier and cheaper to supply a cities energy needs with coal, oil and gas. But in the future there simply won't be anywhere enough coal oil and gas to burn on that scale, and we'll need to move onto solar or nuclear or wind power not because it's more efficient, but because its the only thing we'll have.
With regards to birds and wind turbines, i don't think its a huge problem, but i have no research to back it up, just a hunch.
As for this box, well, sounds like its shaping up to be a kind of fuel cell. Will be interested to see some actual data on its efficiency that's been properly scrutinized by an expert or two, as i'm a little skeptical. But hell, i've heard of some stupid things in my time, including a guy who said he'd build a hand sized fusion power source. He also claimed he'd made a device that could extinglish or ignite fire using just harmonic frequencies. and that the oil companies were trying to kill him... (its been 5 years and i've yet to hear more about this fusion device)